Safety-val



(No Model.) l

G. H. CROSBY.

SAFETY VALVE.

[n1/enfor- Geo. Hanni Patented Oct. 14, 1884.

Unirse Stai-ns Barnim* @rtreeD GEORGE HANNIBAL CROSBY, 0F SOMEBVILLE, lllASSACHUSETTS.

SAFETYHVA Lti'l.

SFECIFICATION forming part of Letters Patent No. 306,386, dated @ci-.ober ld, 18814:. y

Application filed May 5, 15S-l. (No model.)

'b all whom, it may oon/eerie.-

Be it known that I, GEORGE Hartmann Onosnr, of Somerville, in the county of Middlesex, ofthe Coin monwealth of Massachusetts, have invented a new and useful Improvement in Safety-Talves for SteanrBoilers, and l do hereby declare the same to be described in the following speciiication and represented in the accompanying drawings, of which-- Figure l is a vertical .and transverse sec tion ot' a safety-valve and its operative niechanism provided with my invention, the nature of which is defined in the claims hereinafter presented. Fig. 2 is a horizontal and transii'erse section through the line A B of Fig. i. Figs, 3 and a are transverse sections of the improved valve and its seat or seats yas somewhat differently constructed. Fig. 5 is a transverse section, on an enlarged scale, of the dellectorsq and lr and part b of the valve A, as hereinafter described. Figs. 6 and 7 are hereinafter explained.

In Figs. l, 3, and i of such drawings the valve A is represented as a compound one, it in Figs-1 and 3 being shown as composed of a central disk-bearing, a, and a single ring or annular valve-bearing, D, concentric with each other, and connected by arm c, extended from one to the other as the spokes of a wheel do with reference to its hub and rim. In Fig. 4, however, the valve-bearing a is shown as a'n annulus in cross-section. In each of the said figures the valve is represented as provided with a guiding-sleeve, d, that extends upward within the cylindrical case or cover e of the valvespring f, such case c being extended down within and above a tubular casing, 71., and connected therewith by a series of radial arms, t', there being spaces between the arms for the escape oi' the steam in passing through the casing h.. The said casing 71y is screwed upon and extends upward from the valve-seat base B. The sleeve d, n-operly fitted to the inner periphery of the case c, serves with such case not only to guide the valvein its vertical movements, but as a bottoni to the said case c, and thereby as a means of preventing the stean1,when escaping, from impinging against the spring and producing deposits thereon. The sleeve d is connected with the valve by a tapering or Haring neck, 7s, that constitutes a detlector of the steam into the casing h, after the escape of such steam from between the valve-bearings (t and Z). l

In the drawings the central steam inductionpassage through the valveseat base B is shown atl as directly beneath the valve-bearing a, there being around and concentric with the passage Z another induction-passage, m, by which steam is led from the boiler to the annular valve-bearing b.

Extending down ironi the hollow base B is what I term the '/guardpot C, which is a cylindrical or other proper-shaped pot open at top, and having in its sides a series of holes, a. This guard-pot is to prevent the water in the boiler, when suddenly foaming, from being driven upward into and through the valveseat base B, as it is liable to be at times when the said base is wit-hout the said guard or some device for the purpose.

Encompassing and screwed on the base B'is an annulus or gate, D,whieh, on being screwed downward relatiif'ely to the outer end of the passage 0, opening laterally out of the valveseat base, suffices to open such ends or passagesmore or less to interrupt and regulate the egress of steam from them.

Leading downward from the valve-seat are other passages, p, that open into the passage o in manner as represented, each of such pas` sages p being a cylindrical hole bored or made downward in the valveseat base B. In Fig. l two ranges oi such passages are shown,while in Figs. 3 and L but one range of them is represented as in the said base B.

Extending upward from the base and around each range p is an annular rib, @,cr internal deiiectorfor deiiecting steam from the next adjacent valve-seat upward into a downward external annular dctlector, o, projecting from the valve A in manner as represented, such deflector r encompassing the deiiectorqatashort distance from, it. By means of the internal and external deiiectors, q and r, the steam, on the valve being forced upward, will be deflected directly downward upon the base in a manner to aid by its reaction in forcing the valve upward. Each valveannulus a or Z) of the valve has within it and bounded by its periphery an opening, fr, for the escape oi' steam through IOO such opening :trom the valveseat, when the valve is raised from such, such opening being closed when the valve is down upon the base B. Vith this construction of the valve the steam has a greater chance for escape than would be the case were the valve without any such opening or openings. XVere all the escaping steam to be thrown into the deflector, the latter, though performing its duty of aiding in forcing the valve upward, would operate to prevent the free escape of the steam,and therefore by having within the valve an opening or openings, x, as described, much of the steam, as the valve may rise from its seat, can escape through the said opening or openings, and the rest be utilized in acting within and from the delcctor, as described.

Instead of having the detlector o' applied directly to the valve, it may be to the valve-seat base, as shown in Fig. G, in which part of the valve is exhibited at A, the seat-base at B, and the deiiector atl', such deflector extending upward, as shown,with respect to the periphery of the valve. In this case the valve A is without any deflector q; but it may have one, as shown in Fig. 7, in which case the base B should have extending from it the upward dei'lector o. I allude to these arrangements of the delectors, as they are but colorable changes involving the principle of my invention. The valve resting on its seat will be held down thereon by the spring f, against the pressure of the steam in the boiler, to which the Safety-valve may be applied, the tension or pressure of the spring on the valve being increased by screwing downward the screws s over the head of the spring. The areas of the valve that are directly over the passages Z and m are what the steam-pressure ordinarily acts upon toovercome the resistance of the spring. The valve-surface covering each seat will not be so acted on until the valve may rise from such seat. Then the pressure of the steam under the valve is sufricient to move the valve off its seat, steam escaping-will impinge against the tapering deilector 7s, and by it will be deiiected upward within the casing 71, in a manner to aid, rather than retard, the escape of the steam from between the detlectors q and o'. 'Ihe steam will also cross the valve-seats and be driven downward through the passage p into the passages o, out ol" which it will escape, the amount escaping being regulated by the ring D. As soon as the valve is forced off its seat, the steam will be free to act on a greater surface of the valve than it could when the valve rested on its seat, and consequently the valve will-be forced upward with an increased power against the increasing power of its spring, as the spring becomes contracted.

I do not herein claim the ring orgate D adapted to the valve-seat base, aud the passages o thereof; but

I claim- 1. The compound valve A, provided with the concentric bearings a and b, and the deflectors q or r, arranged essentially as set forth, in combination with the valve-seat base B, having the passages o and p, Z and m, and the annular gate D, substantially as specified and represented.

2. The valve provided with the downward deflector in combination with the valve-seat base having the upward deiiector, and the passages p, extending therefrom downward into the passage o, provided with the gate D.

3. rIhe valve A, provided with the guidingsleeve (l and tapering delector la, extending above the said valve, the said deiector constituting a bottom to such sleeve and the spring-case.

4. rIlhe valve provided with the downward deflector, 1*, in combination with the valveseat base having the passages p extending therefrom downward into the passages 0, provided with the gate D, as described.

5. The valve A, having an opening or openings, x, through it for the escape of steam, and also having at its edge or .periphery a downward deflector, r, as described, in combination with the base B, having a seat for and to close each opening` when the valve is resting on such base.

6. 'Ihe open or compound valve A and its seat B, provided with an upward deiiector, r, applied to the periphery of one of them, as set forth.

GEORGE HANNIBAL CROSBY.

-Witn esses:

B. H. EDDY, E. B. PRATT. 

